Fuel heater for internal combustion engines



Dec. 28, 1937. HOLMES 2,103,947

FUEL HEATER FOR INTERNAL domgusuon ENGINES Original Filed F eb. 2a, 1955 z V. K? 329- g 2.9 I I Patented Doc. 28, 1937 PATENT. O FFlCE" rum. HEATER ron manner. cousus'non enemas Holmes, Detroit, Mich.

Application February 2's, 1935, Serial ,No. 8,386

. Renewed May 1'1. 193':

4 Claims. (or, 251-241) a This invention relates to fuel heaters for internal combustion engines, and has particular reference to improvements in means to adapt internal combustion engines of the type which are 5 primarily designed to burn more or less highly refined fuels, such as gasoline, for operation by considerably heavier fuels, such as commercial fuel oil.

As in the case of my prior application, Serial .10 No. 701,902 and in the case of my companion application, Serial No. 8,387, flledof even date herewith, the general object of the present invention is to provide simple, reliable and efficient,

means whereby .ordinary -so--called gasoline l5 engines, such as present day automobile, truck, boat, aircraft and similar engines, may be made to operate economically and wlth'increased power 7 employing as fuel, commercial fuel oil.

Also, as in the case of my afores'aid prior and companion applications, the present invention has in view to provide means whereby an ordinary carburetor employed in conjunction with an ordinary gasoline engine may be used, without change,

for the atomization of relatively heavy fuel, such 25 as commercial fuel oil. To accomplish this purpose it is necessary that the relatively heavy fuel 011 be heated prior to its atomization by the carburetor. Accordingly, thegeneral object of the present invention is to provide a highly 30 efllcient, yet cheap and simple means to utilize exhaust gases flowing from the engine to rapidly raise the temperature of the fuel oil to the desired operating temperature, whereby the engine may be operated on the fuel oil within'the shortest 35 practicable period of time after the engine has beenstarted, it being understood in this connection that in starting the engine, gasoline or equivalent light fuel is used.

With the foregoing and other objects in view,

the invention consists in the novel features of construction, combination and arrangement or,

parts as will be hereinafter more fully described, illustrated in the accompanying drawing and defined in theappended claims.

' 45 In the drawing, wherein like characters of referduit, and which further includes a U-shaped branchcomprislng two spaced, connected pipe sections l5 and I6 communicating with the main pipe I at points spaced longitudinally therealong.

Formingpart of the branch pipe section I! which is disposed nearer the engine as regards the 10 flow of exhaust gases through the exhaust'con- .duit I I, is an enlarged chamber I! which is closed at its ends by plates l8 and I8 and which is formed at one side, preferably near its top, with an enlargement or pocket in which is mounted a 16 thermostat 2| of any suitable type.

Extending through the chamber I1 is aplurality of tubes 22 which, at their ends, extend through the plates i8 and I9 and thereby afford communication between the portions of the pipe 20 section l5 at either end of said chamber. Consequently, exhaust gases may flow fromthe exhaust conduit through the tubes 22 to effect heating of the body of liquid with which said chamberis filled. 25

The chamber I1 is filled with any suitable liquid having a high flash point, and a fuel oil supply line 21 enters said chamber, preferably at thebottom thereof, and within said chamber is wound or coiled as at 28, preferably spirally up- 3 ward, around the tubes 22 and leaves said chamber preferably at or near the top thereof. Consequently, since said coil 28 is submerged in the liquid contained within said chamber, and since the liquid is heated by the exhaust gases, the oil flowing from the source of supply. through the coil 28 to the carburetor also is heated.

The purpose of the unit 13 is not only to heat the fuel oil prior to its delivery to the engine carburetor, but to maintain said oil within a predetermined temperature range, within which range it is best adapted for operating the engine A. The temperature of the liquid in the chamber I1 is, of course, affected by the temperature of the air surrounding said chamber. Moreover, the volume of exhaust gases flowing through the exhaust conduit il varies with changes in the speed of the engine A. Therefore, in order to'maintain the fuel oil within a predetermined temperature range, the volume of exhaust gases which flow through the unit I! must be varied. Accordingly, an exhaust gas deflector member 29 is pivotally mounted within the main pipe section ll of the unit II at a point near the end ofthe branch pipe section "which opens permits substantially unimpeded flow oi exhaust I gases through theexhaust conduit and does not deiiect such gases through the branch pipe II,-

and in theother oi which it serves to deflect a considerable volume of the exhaust gases through 'thebranchpipellandthetubesfloithechamher i I. In intermediate positions of said deflector member a greater or lesser volume oi exhaust gas is deflected through the branch pipe II as is, or course, obvious. I

The thermostat 2| is, as aforesaid, immersed in the body oi liquid contained with the chamber l1 and therefore operates in to changes in the temperature of said body of liquid. In the present instance, said thermostat is illustrated as being of the expansible and contractible bellows type and as including a rod II which extends exteriorly of the chamber i'l andwhich is longitudinally movable with expansion and contraction oi the thermostat. On a bracket carried .by the chamber I1 is intermediately pivoted a lever 3| which is connected at one end with the rod III and at its other end to an arm 32 on the deflector member I! by a rod of link :3. Consequently, in

response to variations in the temperature 0! the liquid within the chamber II, the deflector member 2. is actuated to vary the amount of the exhaustgases which pass through the tubes 22 of the chamber l1 and which are eflective to heat the oil passing through the coil 28 to the carburetor. In this connection, the arrangement is, of course, such that with rise in the temperature of the liquid, and consequently the oil, above a predetermined point the deflectormember Ills actuated todeflect a lesser volume of exhaust gases through the chamber i1, and with fall of the temperature of the-liquid, and consequently the oil, below said 'point the deflector member is actuated to deflect a greater volume of exhaust gases through said chamber. Thus,the unit it is eflective to maintain the oil supplied to the a pressure relief valve. 43 to guard against the development of excessive pressure in said line, said valve being placed in said line at a suitable point between the coil II and the engine carburetor. From said valve a drain line 44 preferably leads to the heavy fuel tank, although it'may lead to any other suitable point. I

From the foregoing described considered in connection with the accompanying drawing, it

is believed that the construction, operation and advantages oi the invention will be clearly understood. It is desired to point out, however, that while certain specific embodiments of the invention have been illustrated herein, the same may be embodied in various other mechanical structures within the. spirit and scope or the invention as deflned in the appended claims.

I claim:- I. A unit for utilizing liquid, said unit comprising a pipe section to'be interposed in a hot gas conducting conduit, a

liquid containing chamber, a plurality oi hot gas conducting tubes extending through saidchamher, a hot gas delivery conduit mm said pipe section to adjacent ends oisaid tubes and lation of hot gases through .saiditubes to heat the liquid contained in said chamber, and a conduit for the liquid to be heated extending through said chamber'and maintaining the liquid therein separated from the liquid in the chamber.

2. A unit for utilizing hot gases to heat a liquid, said unit comprising a pipe section to be interposed in a hot gas conducting conduit, a liquid containing chamber, a plurality of hot gas conducting tubes extending through said chamber, a hot gas delivery conduit leading Irom said pipe section to adjacent ends of said tubes and a hot gas return conduit leading from the other ends of hot gases to heat-a a hot gas return conduit leading from the other 'ends 01' said tubes to said pipe section for circusaid tubes'tosaid pipe section for circulation of hot gases through said tubes to heat the liquid contained in said chamber, and a conduit for the liquid to be heated extending through said.

chamber and maintaining the liquid therein separated from the liquid in the chamber, said conduit for the liquid to be heated being coiled within said chamber about the'hot gas conducting tubes extending therethrough.

3. A unit for utilizing hot gases to heat a liquid, said unit comprising a pipe section to be interposed in a hot gas conducting conduit, aliquid containing chamber, a plurality of hot gas conducting tubes extending through sald chamber, a hot gas delivery conduit leading from said pipe section to a iacent ends of said tubes and a hot gas return conduit leading from the other ends of said tubes to said pipe section for circulation oi! hot gases through said tubes to heat the liquid contained in said chamber, a conduit for the liquid to be heated extending through said chamber and maintaining the liquid therein separated from the liquid in the chamber, 'and .a hot gas deflecting element within said pipe section operable to vary the-amount oi hot gases circulated from said pipe section through said hot gas conducting tubes.

4. A unit for utilizing hot gases to heat a liquid, said unit comprising a pipe section to be interposed in a hot gas conducting conduit, a branch conduit of substantially U-shape including a pair of legs communicating with said pipe section, a liquid containing'chamber interposed in one of the legs of said branch conduitpa plurality oi tubes'extending through said chamber for flow ofrhot gases therethro and a conduit for the liquid to be heated extending through said'chamher and maintaining the liquid therein separated from the liquid in the chamber, said conduit for the liquid to be heated being coiled within said chamber about the hot gas conducting tubes extending therethrough. FREDERICK J. BODIES. 

